Optical fiber connections in optical fiber systems are generally required to have a relatively low signal loss thereat. These connectors used in high-speed single-mode fiber systems also require high return loss in order to avoid instability or noise in a light source which is caused by its reflected light. To this end, it is an accepted practice to polish ends of optical fibers to be connected so as to have planar or slightly convex surfaces which are substantially normal to longitudinal axes of the fibers, and urge the polished optical fiber ends together. One such prior art construction is illustrated in FIG. 1 wherein each optical fiber contact 1, 2 has a substantially convex end face 3, 4, with optical fibers 5, 6 being disposed within first and second longitudinal bores of the first and second contacts 1, 2 respectively. Various materials, e.g. ceramic, metal, glass, have been used for the optical fiber contact bodies in order to ensure that the substantially perpendicular ends 7, 8 of the first and second optical fibers can be formed at apexes of convex end faces 3, 4 by polishing to ensure an accurate mating gap-free interface therebetween. Though connectors utilizing such contacts do exhibit acceptable low loss connections and relatively high return loss, problems with such connectors include a craft sensitive fiber end polishing process and performance degradation caused by small dirt or dust particles between two contacting fiber end faces. Also due to the relatively high stress exerted on the fiber surfaces, these connectors may not function properly in harsh environments which experience high vibration or extreme temperaturs.
To alleviate this problem, a connector referred to by Radiall Corporation as an OPTABALL DF SERIES System has been proposed. This optical fiber contact includes a metal material which has a yet to be ground metal end face prior to fiber insertion in the contact. A glass optical fiber is then disposed within a bore of the optical fiber contact such that its end protrudes from the preground contact end face, and then the fiber end and the metal end face are polished and ground until the end of the fiber is coplanar with the ground and polished contact end face and slanted at an angle. The fiber end and the metal contact end face thus become substantially slanted relative to a longitudinal axis of the fiber, and hence back reflections at the connection are not transmitted to a signal light source generator since the back reflections have an initial angle of reverse propagation which exceeds a critical acceptance angle for the fiber. Though this solution does minimize a magnitude of signals reflected at the connection interface, in practice it is difficult to accuarately form the slanted end of the optical fiber and the metal contact end face conveniently, especially in field installation environments. Hence, this solution is not very craft friendly in practice.